Conventionally, ducts, a reinforce member as a structural member, etc. included in an automobile interior part have typically been formed by bending steel sheets or the like.
However, the automobile interior part such as an instrument panel has been increasingly employing resins to meet requirements such as moldability, shaping flexibility, designing flexibility, corrosion resistivity and weight saving.
Since the automobile interior part such as the instrument panel requires heat resistivity and product stiffness, there has been known a talc-reinforced resin molding formed of a polyolefin resin material such as a polypropylene and a fiber-reinforced resin molding formed of a GFRP (Glass Fiber Reinforced Plastic) that is molded using a glass fiber as a reinforced fiber and a polypropylene as a resin being a thermoplastic resin.
In such automobile interior part, the instrument panel particularly has a lot of functional parts with various functions such as an air conditioning duct, a defroster duct and a meter cluster and has a complex shape. Thus, currently, the automobile interior part is often formed by a method including separately molding a core member and each of the functional parts constituting the automobile interior part and then assembling the separately molded members. However, since the method includes a lot of members, the numbers of fabrication steps and assembly steps become large, which causes manufacturing inefficiency. Especially, a reinforce member as the structural member often uses a bended steel sheet or a metal pipe, so that a total weight becomes heavy when being assembled with other members.
With such background, there has been known an arrangement developed to solve these problems, in which a core member as a principal part of an instrument panel and predetermined functional parts are integrated (see Patent Document 1).
There has been known another arrangement in which a design part made of a soft resin and a core material made of a hard resin are integrated (see Patent Document 2). The core material is typically called a reinforce member or the like, which is designed as a structural member for securing strength and functions as a duct in the above arrangement.
There has been known a still another arrangement in which principal parts are separately molded such that, for instance, each of an upper member, a lower member and a meter hood of an instrument panel is separately molded, and these members are then assembled to form the automobile interior part (see Patent Document 3).
[Patent Document 1] JP-A-7-80915
[Patent Document 2] JP-A-6-198791
[Patent Document 3] JP-A-5-77659